Unmanned aerial vehicles (UAV) (ex.—drones) include aircraft controlled by onboard automated control systems or operated remotely by a human pilot. UAVs of all sizes are useful for both military and civilian applications, but portable multirotor vehicles—essentially miniature helicopters—are simple and accessible enough to be in demand for home and personal use. A quadcopter or quad-rotor UAV, for example, includes four rotors usually fixed in a lightweight airframe, but UAVs with three, five, or six rotors are also common. Regardless of the precise design particulars, personal UAVs operate according to applied physics. A quadcopter may include two pairs of motor-driven rotors, each rotating in the opposite direction at high speeds to produce lift and thrust and enable the UAV to take off and land vertically and to hover in place. Steering and attitude control along multiple axes is achieved through varying the rotational speed of one or more rotors to disturb the equilibrium of the hovering state and induce movement in one or more directions.
The simplicity and agility of a multirotor UAV makes it a useful platform for cyclists, skiers, snowboarders, or other sporting enthusiasts who wish to record their exploits under extreme conditions. For example, the logistics of trailing a cyclist descending a mountain pass, or a basejumper parachuting from a cliff, are complicated for a camera crew (or even a single cameraman) by the problems of safely navigating inaccessible and dangerous terrain at speed while at the same time keeping in view a subject who may repeatedly and unpredictably change position and heading dozens of times per minute. Mounting a video camera to a UAV provides a potential solution to both problems as well as the opportunity for real-time streaming video images for remote viewing. It may therefore be desirable to provide a remotely or autonomously controlled UAV with the means to identify, follow, and provide a continuous video feed of a target subject in motion.